S. diluta Wood.
I first came across this species in Mr. Bullard’s collection from the pond west of Winter Pond, Winchester, Mass. On going over Wood’s description, its identity with S. diluta is unmistakable. The position, color and form of the spore, and the shape of the fertile cells is perfectly represented in Wood’s figure. The dimensions also correspond. Wolle is responsible for confusing this species with S. nitida (Dillw.) Link, but a glance at Wood’s figure is sufficient to show that it is very different from that species. The P. B. A. specimen No. 513 (labelled S. nitida) from Bridgeport, Conn., belongs here. Miss Grace Stone also sent me a collection of this species from near New York City. In the U. S. National Herbarium is another specimen from Bois Sabbi, Louisiana, April 7th, 1891, (A. B. Langlois). Recently the species has been collected at Donnelson, Illinois, by Mr. Frank Harris.
The vegetative cells are usually shorter than in S. nitida, the spores are ovoid, not ellipsoid, and the spore wall is verrucose, or reticulate-verrucose, chestnut brown in color. In herb. E. N. T. Coll. No. 2900.
S. crassa Kützing.
Var. formosa nov. var. Varietas gracilis, cellulis vegetativis 80-95µ × 80-270µ; zygosporis 88-100µ × 120-150µ × 70-90µ; ceterum ut in typo.
A small variety, vegetative cells 80-95µ × 80-270µ: zygospores 88-100µ × 120-150µ × 70-90µ; otherwise similar to the type. Type in herb. E. N. T. Coll. No. 1939. This variety occurs in a pond east of Ashmore, Ill.
S. submaxima Transeau.
This species which was described from Illinois has been found with nearly the same dimensions in the collections from Middlesex Fells, and South Peabody Station, Mass., sent me by Mr. Chas. Bullard.
S. micropunctata nov. sp.
Cellulis vegetativis 30-36µ × 120-300µ, dissepimentis planis, chromatophoris singulis anfractibus arctis 3-7; cellulis fructiferis modo binis vel quaternis inter cellulas vegetativas distributis, modo continuis, altero latere (in quo conjugatio sequitur) inflatis, altero rectis; tubo conjugationis plerumque ex cellula mascula emisso; zygosporis ellipticis 37-42µ × 57-100µ membrana media micropunctata et lutea.